Abstract
Drought and high temperature are two major factors limiting the growth of cool‐season turfgrasses during summer in many areas. The objective of the study was to examine whether the adverse effects of drought and heat alone or in combination on tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.) involve oxidative stress. Grasses were exposed to drought (withholding irrigation), heat (35°C/30°C), and the combined stresses for 30 d in growth chambers. Turf quality (TQ), leaf relative water content (RWC), and chlorophyll content (Chl) decreased with prolonged drought, heat, and combined stresses for both species, but the severity of decline varied with stress type and duration. Transient increases in superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activities occurred at 6 or 12 d of drought and the combined stresses in both species; however, the activities of all three enzymes decreased with extended periods of drought and the combined stresses. The SOD activity was not affected by heat stress alone. The activities of AP and GR were reduced after 18 d of heat stress for both species, but reductions were less than under the combined stresses. The catalase (CAT) activity continued to decrease to below the control level, beginning at 12 d for drought‐stressed or heat‐stressed plants and 6 d for plants exposed to the combined stresses. Lipid peroxidation occurred after 18 d of stresses in both species, as indicated by the increase in malondialdehyde (MDA) content. The results suggested that injuries of drought, heat, or the combined stresses to both tall fescue and Kentucky bluegrass, as manifested by declines in TQ, RWC, and Chl, could be associated with a decrease in antioxidant enzyme activities and an increase in membrane lipid peroxidation.
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Claims 16
Claim · model-written summary
tall fescue turf quality, leaf water content and chlorophyll content declined under prolonged drought, heat and combined stress.
- Taxon
- tall fescue
Lolium arundinaceume7 - Treatment
- prolonged drought, heat, and combined stressese0
- Outcome
- Turf quality (TQ), leaf relative water content (RWC), and chlorophyll content (Chl)e0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“Turf quality (TQ), leaf relative water content (RWC), and chlorophyll content (Chl) decreased with prolonged drought, heat, and combined stresses for both species”
Claim · model-written summary
tall fescue SOD, AP and GR activities increased transiently at 6 or 12 days of drought and combined stress.
- Taxon
- tall fescueLolium arundinaceume7
- Treatment
- drought and the combined stressese0
- Outcome
- superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activitiese0
- Direction
- increasese0
- Qualifier
- at 6 or 12 de0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“Transient increases in superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activities occurred at 6 or 12 d of drought and the combined stresses in both species”
Claim · model-written summary
tall fescue SOD, AP and GR activities decreased with extended drought and combined stress.
- Taxon
- tall fescueLolium arundinaceume7
- Treatment
- extended periods of drought and the combined stressese0
- Outcome
- superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activitiese1
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“the activities of all three enzymes decreased with extended periods of drought and the combined stresses”
e1“superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activities”
Claim · model-written summary
tall fescue SOD activity was unaffected by heat stress alone.
- Taxon
- tall fescueLolium arundinaceume7
- Treatment
- heat stress alonee0
- Outcome
- SOD activitye0
- Direction
- not affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“The SOD activity was not affected by heat stress alone”
Claim · model-written summary
tall fescue AP and GR activities fell after 18 days of heat stress, less than under combined stress.
- Taxon
- tall fescueLolium arundinaceume7
- Treatment
- heat stresse0
- Outcome
- activities of AP and GRe0
- Direction
- reducede0
- Qualifier
- after 18 de0
- Comparator
- combined stressese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“The activities of AP and GR were reduced after 18 d of heat stress for both species, but reductions were less than under the combined stresses”
Claim · model-written summary
tall fescue CAT activity decreased below control from 12 days of drought or heat and from 6 days of combined stress.
- Taxon
- tall fescueLolium arundinaceume7
- Treatment
- drought‐stressed or heat‐stressed plants and 6 d for plants exposed to the combined stressese0
- Outcome
- catalase (CAT) activitye0
- Direction
- decreasee0
- Comparator
- control levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“The catalase (CAT) activity continued to decrease to below the control level, beginning at 12 d for drought‐stressed or heat‐stressed plants and 6 d for plants exposed to the combined stresses”
Claim · model-written summary
tall fescue lipid peroxidation occurred after 18 days of stress, indicated by increased MDA content.
- Taxon
- tall fescueLolium arundinaceume7
- Outcome
- Lipid peroxidatione0
- Qualifier
- after 18 d of stressese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“Lipid peroxidation occurred after 18 d of stresses in both species, as indicated by the increase in malondialdehyde (MDA) content”
Claim · model-written summary
tall fescue injury may be associated with reduced antioxidant enzyme activity and increased membrane lipid peroxidation.
- Taxon
- tall fescueLolium arundinaceume7
- Treatment
- drought, heat, or the combined stressese0
- Outcome
- injuries of drought, heat, or the combined stressese0
- Direction
- declinese0
- Qualifier
- could be associated with a decrease in antioxidant enzyme activities and an increase in membrane lipid peroxidatione0
Not reportedOrgan / stage
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“injuries of drought, heat, or the combined stresses to both tall fescue and Kentucky bluegrass, as manifested by declines in TQ, RWC, and Chl, could be associated with a decrease in antioxidant enzyme activities and an increase in membrane lipid peroxidation”
Claim · model-written summary
Kentucky bluegrass turf quality, leaf water content and chlorophyll content declined under prolonged drought, heat and combined stress.
- Taxon
- Kentucky bluegrass
.jpg?width=60)
Poa pratensise7 - Treatment
- prolonged drought, heat, and combined stressese0
- Outcome
- Turf quality (TQ), leaf relative water content (RWC), and chlorophyll content (Chl)e0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“Turf quality (TQ), leaf relative water content (RWC), and chlorophyll content (Chl) decreased with prolonged drought, heat, and combined stresses for both species”
Claim · model-written summary
Kentucky bluegrass SOD, AP and GR activities increased transiently at 6 or 12 days of drought and combined stress.
- Taxon
- Kentucky bluegrassPoa pratensise7
- Treatment
- drought and the combined stressese0
- Outcome
- superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activitiese0
- Direction
- increasese0
- Qualifier
- at 6 or 12 de0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“Transient increases in superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activities occurred at 6 or 12 d of drought and the combined stresses in both species”
Claim · model-written summary
Kentucky bluegrass SOD, AP and GR activities decreased with extended drought and combined stress.
- Taxon
- Kentucky bluegrassPoa pratensise7
- Treatment
- extended periods of drought and the combined stressese0
- Outcome
- superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activitiese1
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“the activities of all three enzymes decreased with extended periods of drought and the combined stresses”
e1“superoxide dismutase (SOD), ascorbate peroxidase (AP), and glutathione reductase (GR) activities”
Claim · model-written summary
Kentucky bluegrass SOD activity was unaffected by heat stress alone.
- Taxon
- Kentucky bluegrassPoa pratensise7
- Treatment
- heat stress alonee0
- Outcome
- SOD activitye0
- Direction
- not affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“The SOD activity was not affected by heat stress alone”
Claim · model-written summary
Kentucky bluegrass AP and GR activities fell after 18 days of heat stress, less than under combined stress.
- Taxon
- Kentucky bluegrassPoa pratensise7
- Treatment
- heat stresse0
- Outcome
- activities of AP and GRe0
- Direction
- reducede0
- Qualifier
- after 18 de0
- Comparator
- combined stressese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“The activities of AP and GR were reduced after 18 d of heat stress for both species, but reductions were less than under the combined stresses”
Claim · model-written summary
Kentucky bluegrass CAT activity decreased below control from 12 days of drought or heat and from 6 days of combined stress.
- Taxon
- Kentucky bluegrassPoa pratensise7
- Treatment
- drought‐stressed or heat‐stressed plants and 6 d for plants exposed to the combined stressese0
- Outcome
- catalase (CAT) activitye0
- Direction
- decreasee0
- Comparator
- control levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“The catalase (CAT) activity continued to decrease to below the control level, beginning at 12 d for drought‐stressed or heat‐stressed plants and 6 d for plants exposed to the combined stresses”
Claim · model-written summary
Kentucky bluegrass lipid peroxidation occurred after 18 days of stress, indicated by increased MDA content.
- Taxon
- Kentucky bluegrassPoa pratensise7
- Outcome
- Lipid peroxidatione0
- Qualifier
- after 18 d of stressese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“Lipid peroxidation occurred after 18 d of stresses in both species, as indicated by the increase in malondialdehyde (MDA) content”
Claim · model-written summary
Kentucky bluegrass injury may be associated with reduced antioxidant enzyme activity and increased membrane lipid peroxidation.
- Taxon
- Kentucky bluegrassPoa pratensise7
- Treatment
- drought, heat, or the combined stressese0
- Outcome
- injuries of drought, heat, or the combined stressese0
- Direction
- declinese0
- Qualifier
- could be associated with a decrease in antioxidant enzyme activities and an increase in membrane lipid peroxidatione0
Not reportedOrgan / stage
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“tall fescue ( Festuca arundinacea L.) and Kentucky bluegrass ( Poa pratensis L.)”
e0“injuries of drought, heat, or the combined stresses to both tall fescue and Kentucky bluegrass, as manifested by declines in TQ, RWC, and Chl, could be associated with a decrease in antioxidant enzyme activities and an increase in membrane lipid peroxidation”
The same questions in other papers
heat · quality: general · Lolium arundinaceum (tall fescue)Positive and negative results
1 in the opposite direction
- positive
drought · physiology: antioxidant enzymes · Lolium arundinaceum (tall fescue)Positive and negative results
2 in the opposite direction
- negative
- negative
drought · quality: general · Poa pratensis (Kentucky bluegrass)Positive and negative results
2 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- negative
1 paper more in this group
See all 5 papers →drought · physiology: antioxidant enzymes · Poa pratensis (Kentucky bluegrass)Positive and negative results
3 papers in the same direction as this paper · 4 in the opposite direction
- negative
- no effect
- negative
4 papers more in this group
See all 8 papers →heat · quality: general · Poa pratensis (Kentucky bluegrass)Results agree
1 paper in the same direction as this paper
- negative
heat · physiology: antioxidant enzymes · Poa pratensis (Kentucky bluegrass)Results agree
3 papers in the same direction as this paper
- negative
- negative
- negative
heat · physiology: antioxidant enzymes · Lolium arundinaceum (tall fescue)Results agree
3 papers in the same direction as this paper
- negative
- no effect
- negative
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.